Types of Queue

Types of Queue

In this tutorial, you will learn different types of queue along with illustration.

A queue is a useful data structure in programming. It is similar to the ticket queue outside a cinema hall, where the first person entering the queue is the first person who gets the ticket.

There are four different types of queue in data structure. Let's discuss them below.


Simple Queue

In a simple queue, insertion takes place at the rear and removal occurs at the front. It strictly follows FIFO rule.

Simple queue
Simple queue

Please visit queue to learn more about a simple queue and its implementation in different programming languages.


Circular Queue

In a circular queue, the last element points to the first element making a circular link.

Circular queue
Circular queue

The main advantage of a circular queue over a simple queue is better memory utilization. If the last position is full and the first position is empty then, an element can be inserted in the first position. This action is not possible in a simple queue.

Please visit circular queue to learn more about the circular queue.


Priority Queue

A priority queue is a special type of queue in which each element is associated with a priority and is served according to its priority. If elements with the same priority occur, they are served according to their order in the queue.

Priority queue
Priority queue

Insertion occurs based on the arrival of the values and removal occurs based on priority.

Please visit priority queue to learn more about priority queue.

Double Ended Queue or Deque

Double Ended Queue is a type of queue in which insertion and removal of elements can be performed from either from the front or rear. Thus, it does not follow FIFO rule (First In First Out).

Double ended queue
Double ended queue

Please visit double ended queue to learn more about double ended queue.